Elimination of organohalo and oxirane species in carboxylic acid ester streams

ABSTRACT

The present technology provides a process of reducing, removing or eliminating organohalo, glycidol, and oxirane species from carboxylic acid esters streams and crude and refined triglyceride oils to provide a carboxylic acid ester stream or triglyceride oil with reduced levels or essentially free of organohalo, glycidyl or other oxirane species. The process includes adding to the carboxylic acid ester stream or triglyceride oil an amount of a carboxylate anion and a cation counterion sufficient to react with the organohalo, glycidyl and oxirane species present.

CROSS REFERENCE TO RELATED APPLICATIONS

This application a U.S. nationalization under 35 U.S.C. § 371 ofInternational Application No. PCT/US2011/050289, filed Sep. 2, 2011,which claims priority to U.S. Provisional Application No. 61/380,013,filed on Sep. 3, 2010, with the title “Elimination of Oraganohalo andOxirane Species in Carboxylic Acid Ester Streams,” the contents of whichare herein incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

3-chloro-1,2-propanediol (3-MCPD) is a well known organic chemicalcompound formed in foods. It is a byproduct of food processing,especially in heat processed, fat-containing foodstuff, where 3-MCPD isformed during the processing.

Recent studies have identified high levels of 3-MCPD esters in refinedfats and oils, including edible oils. 3-chloro-1,2-propanediol (3-MCPDs)and their esters have been found in all refined vegetable oils. Theprocessing and refining of oils leads to formation of these unwantedbyproducts, organohalo species (for example, 3-chloro-1,2-propanediol(MCPDs)) and glycidol and their respective esters. Free MCPD has beenfound to exhibit genotoxic and carcinogenic effects in testing, andthese effects have raised some concern, especially in the food industry.Glycidol is also a known genotoxic and carcinogenic compound. Notoxicological profiles are known for the 3-MCPD esters or glycidylesters. These esters' toxicities depend on their breakdown by lipases inthe gut to the free 3-MCPD or glycerol species, which is a current areaof concern and study.

Currently, there is limited and contradictory knowledge available aboutwhen and how 3-MPCD-esters are formed during the oil refining process.The highest 3-MPCD ester contents are found in refined oils whereasvirgin or non-refined oils have lower content, sometimes below detectionlimits. There is some belief that heat pre-treatment of the seed (orfruit) may contribute to the levels in non-refined oils. Research intothe mechanism of 3-MCPD/glycidol-ester formation is ongoing in thefield.

BRIEF SUMMARY OF THE INVENTION

There is a need in the art to limit or eliminate the amounts of 3-MCPDand glycidol and their respective esters within fats and oils,especially in edible oils. The present technology provides one or moreunique processes of providing fatty acid glyceride streams andtriglyceride oils free of organohalo (e.g., 3-chloro-1,2-propandiol),glycidyl or other oxirane species, such as epichlorohydrin, and theirrespective esters. The processes include both treating oils and/ortreating the processing stream used in the making and/or processing ofcrude or refined oils by the addition of one or more bases. The processincludes adding one or more bases to either 1) a triglyceride oil, or 2)to a carboxylic acid ester stream used in the preparation oftriglyceride oil. The one or more bases react with a fatty acid or afatty acid ester within the carboxylic acid stream or triglyceride oilto form a carboxylate anion (soap) and a cation counterion. In someembodiments, additional fatty acid is added with the one or more basesto form the carboxylate anion. The carboxylate anion then reacts withthe organohalo or oxirane species to yield an ester and metal halidesalt or a metal alkoxide species, respectively. This provides a fattyacid glyceride stream or triglyceride oil with reduced levels oforganohalo (e.g., 3-chloro-1,2-propandiol), glycidyl esters or otheroxirane species. In some embodiments, the fatty acid glyceride stream ortriglyceride oil is essentially free of organohalo, glycidyl esters orother oxirane species.

In one aspect, the present technology provides at least one process ofpreparing a carboxylic acid ester stream with reduced levels oressentially free of organohalo, glycidyl or other oxirane species. Theprocess comprises adding to the carboxylic acid ester stream aneffective amount of a carboxylate anion and a cation counterion to reactwith the organohalo, glycidyl and oxirane species present in thecarboxylic acid ester stream at a temperature of about 80° C. to about275° C., preferably about 80° C. to about 250° C., more preferably about140° C. to about 250° C., for a sufficient time to provide a carboxylicacid ester stream with reduced levels or essentially free of organohalo,glycidyl or other oxirane species.

In some aspects, the present technology prevents the formation oforganohalo, glycidyl or other oxirane species in a carboxylic acid esterstream or triglyceride oil.

In another aspect, the present technology provides at least one processof removing organohalo, glycidyl or other oxirane species from atriglyceride oil comprising the steps of mixing an effective amount ofone or more bases to an effective amount of at least one fatty acid toproduce an effective amount of a carboxylate anion and correspondingcation counterion that is sufficient to reduce or remove the organohalo,glycidyl or other oxirane species from the triglyceride oil; mixing theeffective amount of the carboxylate anion with the triglyceride oil at atemperature of about 80° C. to about 275° C., preferably about 80° C. toabout 250° C., more preferably about 140° C. to about 250° C., for asufficient time; wherein the oil has reduced levels or essentially freeof organohalo, glycidyl or other oxirane species.

In yet a further aspect, the present technology provides a process ofreducing, removing, or preventing the formation of organohalo, glycidylor other oxirane species during processing or a manufacturing procedurefor a triglyceride oil comprising the steps of making a triglyceride oilfeedstock; adding a sufficient amount of one or more bases to react witha fatty acid within the triglyceride oil feedstock to produce asufficient amount of a carboxylate anion and a cation counterion toreact with the organohalo, glycidyl and other oxirane species present inthe feedstock; incubating the feedstock and one or more bases at atemperature of about 80° C. to about 275° C., preferably about 80° C. toabout 250° C., more preferably about 140° C. to about 250° C., for asufficient time to produce a triglyceride oil substantially free oforganohalo, glycidyl or other oxirane species. In some aspects, the oneor more bases are added at the start of the oil processing ormanufacturing procedure. In other aspects, the process further comprisesadding a sufficient amount of a fatty acid to react with the one or morebases to produce the carboxylate anion and cation counterion.

In some aspects, the triglyceride oil or carboxylic acid ester streamcomprises less than about 0.5 ppm of organohalo, glycidyl or otheroxirane species, preferably less than about 0.15 ppm, alternatively lessthan about 0.1 ppm.

DETAILED DESCRIPTION OF THE INVENTION

The present technology surprisingly provides a method of removing,reducing, eliminating or preventing the formation of organohalo species,glycidyl, or other oxiranes, such as for example, epichlorohydrin, ortheir respective esters from carboxylic acid esters streams and crudeand refined triglyceride oils. The methods provide resultant carboxylicacid ester streams or triglyceride oils that are reduced or, in someembodiments, essentially free of organohalo, glycidyl or other oxiranespecies.

The term “reduced” organohalo, glycidyl or other oxirane species inrelation to the present technology is defined as a reduction by at least25% or more, preferably at least 40% in the amount of the organohalo,glycidyl or other oxirane species in the carboxylic acid ester streamsor crude and refined triglyceride oil when compared to the carboxylicacid ester stream or triglyceride oil not treated with a base as in thepresent technology. In some embodiments, the amount of the organohalo,glycidyl, or other oxirane species are reduced by at least about 25% ormore, at least about 30% or more, alternatively about 35% or more,alternatively about 40% or more, alternatively about 45% or more,alternatively about 50% or more, alternatively about 55% or more,alternatively about 60% or more, alternatively about 70% or more,alternatively about 80% or more, alternatively about 90% or more, andinclude any percentages there between, including, but not limited to,increments of about 0.1%, about 0.2%, about 0.25%, about 0.3%, about0.4%, about 0.5%, about 0.6%, about 0.7%, about 0.8%, about 0.9%, about1% and multiple factors thereof (e.g. about 0.5×, about 1×, about 2.0×,about 2.5×, etc).

The term “essentially free of” organohalo, glycidyl or other oxiranespecies for the present technology is defined as levels of theorganohalo, glycidyl or other oxirane species which are very low levels,for example, less than about 0.5 ppm, more preferably less than about0.15 ppm, alternatively less than about 0.1 ppm of the compositions ofthe oil. In some embodiments, “essentially free of” would encompassundetectable levels of these compounds. The amount of organohalo,glycidyl or other oxirane species within the oil can be calculated orestimated by any means known in the art, including gas chromatography(GC) mass spectrometry, liquid chromatography (LC) mass spectrometry andthe like. Commercial laboratories that can perform these measurementsinclude, but are not limited to, Eurofins Central AnalyticalLaboratories, Metairie, La. and SGS Gmbh, Hamburg, Germany.

In some embodiments, the present technology provides a process fortreating both refined and unrefined oil and/or treating the processingcarboxylic acid ester stream in the making or processing of refined oilsto reduce, remove or prevent the formation of the organohalo, glycidylor other oxirane species from the end-product oil. Not to be bound byany theory, but by information and belief, it is believed that theaddition of one or more bases to the carboxylic acid ester stream duringmanufacturing of a triglyceride oil prevents the formation of one ormore organohalo, glycidyl or oxirane species from forming in the endproduct triglyceride oil.

In some embodiments, the present technology provides a process oftreating a carboxylic acid ester stream in the process of making an oilto prevent the formation of organohalo, glycidyl or oxirane species.

Treating Triglyceride Oil During Processing

In some embodiments, the present technology provides a process forproducing carboxylic acid ester streams with reduced levels oressentially free of organohalo species (e.g., 3-chloro-1,2-propandiol),glycidol or oxirane species and their respective esters. The processinvolves chemically modifying the organohalo, glycidyl or oxiranespecies from the oil so that it can be separated out from the carboxylicacid ester stream, in some instances by filtration. The process includesadding at least one base either during the processing and/or manufactureof a carboxylic acid ester stream or after the carboxylic acid esterstream is produced into a triglyceride oil. The at least one base reactswith a fatty acid or a fatty acid ester within the carboxylate acidstream to form a carboxylate anion (soap) and its cation counterion asdepicted below:

wherein R represents a carbon chain length from C₁ to C₂₃ and wherein Mis an alkali metal, an alkaline earth metal, a transition metal, or anitrogen- or phosphorous-containing cationic species. The carboxylateanion and cation counterion reacts with the organohalo or glycidylspecies to yield an ester and metal halide salt or a metal alkoxidespecies, respectively as shown below:

wherein R represents a carbon chain length from C₂ to C₂₄ and wherein Mis an alkali metal, an alkaline earth metal, a transition metal, or anitrogen- or phosphorous-containing cationic species. In someembodiments, the metal halide salt formed can be filtered out from therefined or processed carboxylic acid stream, providing a filteredcarboxylic acid ester stream with reduced levels or essentially free oforganohalo (e.g., 3-chloro-1,2-propandiol), glycidol or oxirane speciesand their respective esters.

In the present technology, carboxylic acid ester streams include, butare not limited to, any compound or components within the stream ofmanufacturing, refining, processing or purifying fats and oils,including, but not limited to, fats, oils, fatty acids and glycerols andthe like. The terms fatty acid and carboxylic acids are interchangeablefor use in the present application. Fats and oils include, but are notlimited to, any triglyceride oils, including raw and purified oils,vegetable oils, animal fat, and synthetic oils. Fats and oils arecomposed of triglycerides, esters of glycerol and fatty acids. Naturalfats and oils are composed principally of triglycerides, but othercomponents may be present in minor quantities, including, but notlimited to, fatty acids, partial glycerides, diglycerides andmonoglycerides. Triglycerides are also called triacylglycerols (TAG) andare esters derived from glycerol and three fatty acids. Suitabletriglyceride oils include, but are not limited to coconut oil, cochinoil, corn oil, cottonseed oil, linseed oil, olive oil, palm oil, palmkernel oil, peanut oil, soybean oil, sunflower oil, tall oils, tallow,lesquerella oil, tung oil, whale oil, tea seed oil, sesame seed oil,safflower oil, rapeseed oil, fish oils, avocado oil, mustard oil, ricebran oil, almond oil, walnut oil, derivatives thereof, and combinationsthereof.

In some embodiments, the processes of manufacturing, refining,processing or purifying fats and oils include any process known to oneskilled in the art. These processes include, but are not limited to,physical, steam or mechanical refining (including, but not limited to,for example, vacuum steam distillation), chemical refining (including,but not limited to, for example, solvent extraction and miscellarefining), and treatment by bleaching clay, basic or acidic resin,silica, alumina and/or active carbon. In the present technology,organohalo, glycidyl or other oxirane species are removed by theaddition of at least one base during the processing steps of thetriglyceride oil or carboxylic acid ester stream. The at least one basemay be added at the beginning of the processing or manufacturing step,during the processing and manufacturing steps, or after the processingor manufacturing steps of a triglyceride oil. If added during theprocessing or after the processing of the triglyceride oils, additionalfatty acids may also be added to produce sufficient amounts of thecarboxylate anion and counter cation, or alternatively already formedcarboxylate anion and counter cation may be added.

In the present technology, the at least one base is added in an amountsufficient to remove a sufficient amount of the organohalo, glycidyl orother oxirane species from the triglyceride oil or carboxylic acidstream. A sufficient amount of the at least one base includes an amountable to react with a sufficient amount of fatty acid to produce asufficient amount of carboxylate anion and cation counterion to reactwith organohalo, glycidyl or other oxirane species present or formedduring the processing or manufacturing to reduce the amount oforganohalo, glycidyl or oxirane species or, in some embodiments, producean oil that is substantially free of organohalo, glycidyl or oxiranespecies. If the at least one base is added at the beginning or duringthe processing or manufacturing of the triglyceride oil, the at leastone base can be added in excess of the amount of organohalo, glycidyl orother oxirane species anticipated to be formed in the final end-producttriglyceride oil. The anticipated amount of organohalo, glycidyl orother oxirane species can be estimated by one skilled in the artfamiliar with manufacturing and processing techniques, and can also bedetermined by measuring the amount of organohalo, glycidyl or oxiranespecies in the untreated oil.

In some embodiments, the amount of based added during processing ormanufacturing of the oil is about 100 parts per million (ppm) to about2% based on total weight of the triglyceride oil, preferably about 200ppm to about 2% based on total weight of the triglyceride oil. The basecan be added in an excess of the organohalo, glycidyl or other oxiranespecies present or anticipated to be formed, preferably about 1.1 foldto about 10,000 fold excess, preferably about 1.1 fold to about 20 foldexcess, preferably about 2 fold to about 10 fold excess. Alternatively,the base can be added in excess of the organohalo, glycidyl or oxiranespecies present or anticipated in about 1.1 fold to about 1,000 foldexcess, alternatively from about 1.1 fold to about 500 fold excess,alternatively from about 1.1 fold to about 250 fold excess,alternatively from about 1.1 fold to about 100 fold excess,alternatively from about 1.1 fold to about 50 fold excess, alternativelyfrom about 1.1 fold to about 25 fold excess, alternatively from about1.1 fold to about 20 fold excess, alternatively from about 2 fold toabout 1000 fold excess, alternatively from about 2 fold to about 500fold excess, alternatively from about 2 fold to about 250 fold access,alternatively from about 2 fold to about 100 fold excess, alternativelyfrom about 2 fold to about 50 fold excess, alternatively from about 2fold to about 25 fold excess, and includes any percentage or range therebetween, including, but not limited to, increments of about 0.1, about0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8,about 0.9 or about 1.0 fold and multiplied factors thereof (e.g. about0.5×, about 1.0×, about 2.0×, about 2.5×, about 3.0×, about 4.0×, about5.0×, about 10×, about 50×, or 100× or greater). In some embodiments,the fold excess can be about 2 fold, about 3 fold, about 4 fold, about 5fold, about 6 fold, about 7 fold, about 8 fold, about 9 fold, about 10fold, about 11 fold, about 12 fold, about 13 fold, about 14 fold, about15 fold, about 16 fold, about 17 fold, about 18 fold, about 19 fold,about 20 fold, about 21 fold, about 22 fold, about 23 fold, about 24fold, about 25 fold, about 30 fold, about 35 fold, about 40 fold, about45 fold, about 50 fold, about 55 fold, about 60 fold, about 65 fold,about 70 fold, about 75 fold, about 80 fold, about 85 fold, about 90fold, about 95 fold, about 100 fold, about 105 fold, about 110 fold,about 115 fold, about 120 fold, about 125 fold, about 130 fold, about135 fold, about 140 fold, about 145 fold, about 150 fold, about 175fold, about 200 fold, about 250 fold, about 300 fold, about 350 fold,about 400 fold, about 450 fold, about 500 fold excess of base.

In some embodiments, the one or more bases is added in a sufficientamount to produce at least about 350 ppm or more of the carboxylateanion (soap) or cation counterion within the carboxylic acid esterstream or triglyceride oil, preferably at least about 400 ppm or more,to react with the organohalo, glycidyl or other oxirane species. In someembodiments, a sufficient amount of the carboxylate anion or cationcounterion may be directly added to the carboxylic acid ester stream orthe unrefined or refined triglyceride oil, wherein the sufficient amountis at least about 350 ppm or more, more preferably about 400 ppm ormore. In some embodiments, the amount of the carboxylate anion formed oradded includes, but is not limited to, about 350 ppm or more, about 400ppm or more, about 450 ppm or more, about 500 ppm or more, about 550 ppmor more, about 600 ppm or more, about 650 ppm or more, about 700 ppm ormore, about 800 ppm or more, about 900 ppm or more, about 1000 ppm ormore, about 1200 ppm or more, about 1500 ppm or more, about 1800 ppm ormore, about 2000 ppm or more, about 2500 ppm or more, and includes anyppm amount there between, including, but not limited to, for example,increments of about 0.1 ppm, about 0.25 ppm, about 0.5 ppm, about 1 ppm,about 2 ppm, about 5 ppm, about 10 ppm, about 20 ppm, about 25 ppm,about 50 ppm, about 100 ppm, and multiple factors thereof (e.g. about0.5×, about 1.0×, about 2×, about 2.5×, about 5×, etc).

The at least one base can be added during any step of the processingand/or manufacturing of the triglyceride oil, including, but not limitedto, refining, degumming, deodorizing, washing, bleaching, distillation,refining, and the like and any combination thereof. In some embodiments,depending on what stage of the processing/manufacturing of the oil theone or more bases is added, free fatty acid can also be added in anamount sufficient to react with the one or more bases to produce asufficient amount of carboxylate anion to reduce or remove theorganohalo, glycidyl or other oxirane species from the end-product oiland provide an oil with reduced levels or essentially free oforganohalo, glycidyl or other oxirane species. Preferably, a fatty acidnaturally found in the oil being manufactured or processed is used.

The reaction of the carboxylate anion (and cation counterion) with theorganohalo, glycidyl or other oxirane species occurs at a temperature ofabout 80° C. to about 275° C., alternatively about 80° C. to about 250°C., preferably about 120° C. to about 275° C., preferably about 140° C.to about 240° C., more preferably about 180° C. to about 230° C., andincludes any ranges or temperatures there between, including incrementsof about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6,about 0.7, about 0.8, about 0.9, about 1.0 and multiple factors thereof(e.g. about 0.5×, about 1×, about 2×, about 3×, about 4×, about 5×,about 10×). Suitable temperatures include, but are not limited to, about80° C., about 90° C., about 100° C., about 110° C., about 120° C., about130° C., about 140° C., about 150° C., about 160° C., about 170° C.,about 180° C., about 190° C., about 200° C., about 210° C., about 220°C., about 230° C., about 240° C., about 250° C., about 260° C., about270° C., about 275° C. and includes any temperature there between inincrements of about 0.1, about 0.2, about 0.25, about 0.3, about 0.4,about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0 andmultiple factors thereof.

The reaction is maintained for a sufficient time until the triglycerideoil is essentially free of organohalo, glycidyl or other oxiranespecies. Suitable reaction times include, but are not limited to, about30 minutes or more, preferably about one hour or more, and include, butare not limited to, for example, about 30 minutes or more, about 45minutes or more, about 50 minutes or more, about one hour or more, abouttwo hours or more, about three hours or more, about four hours or more,about 5 hours or more, about 6 hours or more, about 7 hours or more andincludes any amounts of time there between. Reaction times will dependon both the amount of the carboxylate anion and cation counter ionpresent in the reaction mixture and the reaction temperature. Ingeneral, the reaction time will be longer when a temperature at thelower end of the temperature range is used, and shorter when atemperature at the high end of the temperature range is used. Similarly,reaction times will be longer when amounts of carboxylate anion andcation counterion present in the reaction stream are at the lower end ofthe range, for example at about 350 ppm to about 400 ppm, and will beshorter when amounts greater than about 400 ppm are present.

In one embodiment, the present technology includes a process of reducingor removing organohalo, glycidyl or other oxirane species from atriglyceride oil comprising the steps of mixing an effective amount ofthe one or more bases with an effective amount of at least one fattyacid to produce an effective amount of a carboxylate anion andcorresponding cation counter ion that is sufficient to reduce or removethe organohalo, glycidyl or other oxirane species from the triglycerideoil; and mixing the effective amount of the carboxylate anion withtriglyceride oil at a temperature of about 80° C. to about 275° C.,alternatively about 80° C. to about 250° C., preferably 140° C. to about250° C. In some embodiments, the reacted mixture is then filtered bymethods known in the art, for example, but not limited to, filter pressor bag filter, to remove the halide salt species formed. The filteredoil has reduced levels or is essentially free of organohalo, glycidyl orother oxirane species.

During the manufacture and processing of a triglyceride oil, free fattyacids are found within these oils which are usually removed during thefurther processing steps of, for example, physical or chemical refiningor deodorization. In the present technology, fatty acids found withinthe triglyceride oils can be used to react with the added base and/orbases to produce the carboxylate anion (and cation counter ion).Depending on how much free fatty acid is within the triglyceride oil,additional fatty acid can be added to produce a sufficient amount ofcarboxylate anion (and cation counterion) to react with the organohalo,glycidyl or other oxirane species present or estimated in thetriglyceride oil or carboxylic acid ester stream.

Removal of Organohalo, Glycidyl or Other Oxirane Species from RefinedOil or after Processing of the Triglyceride Oil

In some embodiments of the present technology, the triglyceride oil isalready processed, for example a refined or unrefined fatty acid oil. Inthis process, a sufficient amount of one or more bases is added (and ifnecessary, additional amount of at least one fatty acid) to produce asufficient amount of carboxylate anion (and cation counterion) to reactwith the amount of organohalo, glycidyl or other oxirane species withinthe oil. The amount of organohalo, glycidyl or other oxirane specieswithin the oil can be calculated or estimated by any means known in theart, including gas chromatography (GC) mass spectrometry, liquidchromatography (LC) mass spectrometry and the like. In the case ofrefined oils, the fatty acids have been removed during the refiningprocedure and thus fatty acids are also added along with the one or morebases. In the case of non-refined oils some free fatty acids may beavailable to react with the one or more bases, and thus some or no extrafatty acids can be added with the one ore more bases, depending on thetype of oil.

In some embodiments, at least one base is reacted with fatty acids(preferably a fatty acid which is natively found within thetriglyceride) to create the carboxylate anion. The carboxylate anion isthen reacted with the triglyceride oil to reduce or remove organohalo,glycidyl or other oxirane species. The carboxylate anion is added in asufficient amount to reduce or remove a sufficient amount of theorganohalo, glycidyl or other oxirane species to provide a triglycerideoil with reduced levels or essentially free of organohalo, glycidyl orother oxirane species. A sufficient amount of carboxylate anion is, asdescribed above, at least about 350 ppm, alternatively at least about400 ppm or more. This reaction is carried out as described above, at atemperature of about 80° C. to about 275° C., alternatively about 80° C.to about 250° C., preferably about 120° C. to about 275° C. A sufficientamount of time is, as described above, greater than about 30 minutes,alternatively an hour or more, alternatively two hours or more.

The carboxylate anion can be reacted with the triglyceride oil indifferent ways. For example, the carboxylate anion can be generated inor added to the reactor in which the triglyceride oil was formed (singlepot method). Alternatively, the triglyceride oil can be added to asecond reactor or a series of reactors, and the carboxylate anion can beadded to the second reactor or the series of reactors (sequentialmethod). In a further embodiment, triglyceride oil streams can flow overa reactor bed containing the carboxylate anion and cation counterion.

Carboxylate anions and their cation counterion of the present technologyinclude metal carboxylates of the following structure:

wherein R is C₂ to C₂₄ and M is an alkali metal, an alkaline earthmetal, a transition metal, or a nitrogen- or phosphorous-containingcationic species. Any suitable alkali metal, alkaline earth metal ortransition metal may be used, including, but not limited to, forexample, iron, copper, calcium, magnesium, aluminum, potassium, sodium,and the like. In some preferred embodiments, the metals that can be usedin edible oils are preferably those that are found naturally in thebody, including, but not limited to, calcium, magnesium, copper,potassium, sodium, and the like. The metal can be chosen based on anumber of factors, including, but not limited to, cost and finalapplication. Suitable final applications include, but are not limitedto, for example, edible foods, pet food, cosmetics, flavor carriers,pharmaceuticals and the like.

The oils or carboxylic acid ester streams of the present technology arefiltered using standard filtering techniques known in the art. In someembodiments, the oils are filtered using standard filtration equipment,including, but not limited to, for example, a bag filter, cartridgefilter or plate and frame filter press. Typical filter pore sizes forthese filters include pore sizes in the range of about 0.5 microns toabout 100 microns. If necessary, a filtering aid such as diatomaceousearth or kieselguhr could be used to improve the filtration process.

Processes other than filtration can also be used to remove the resultingmetal halide salt or metal alkoxide species from the oils or carboxylicacid ester streams. Such other processes that can be used include, butare not limited to, washing, centrifuging, winterization, extraction,acidification with a mineral acid, settling and miscella refining.

Any suitable fatty acids (carboxylic acids) may be used in theprocessing of making carboxylic acid ester streams, including, but notlimited to, fatty acids derived from animal and vegetable sources, anyfeedstocks known in the art, including, but are not limited to, an alkylester of a carboxylic acid, carboxylic anhydride or carboxylicderivatives such as halides (acyl halides), carbonates, othercarboxylate species, (e.g., mixed anhydrides) or heteroatom derivatives,such as, for example imidazolides, ortho esters, silyl esters,hydrazines.

In the present technology, any suitable base can be used that can reactwith the fatty acid to produce a carboxylate anion. Suitable basesinclude, but are not limited to, for example, carbonate, bicarbonate,hydroxide, oxide, alkoxide, amine bases, hydrides, phosphines and thelike. In some embodiments, the one ore more bases are added in excess ofthe amount of organohalo, glycidyl or other oxirane species in thecarboxylic acid ester stream or triglyceride oil.

In one embodiment, the present technology provides a method of removingorganohalo, glycidyl or other oxirane species from short and mediumchain triglycerides (for example, short chain fatty acids have from 2-5carbons and medium chain triglycerides have from 6-10 carbons) bydeodorizing the triglyceride oil after addition of the carboxylate anionand cation counterion and described above. The process of deodorizationincludes the standard deodorization steps known in the art, for example,such steps can include heating the mixture for about 20 to about 30minutes at a temperature of about 180° C. to about 200° C. under vacuumof about 2 mmHg to about 15 mmHg, and running steam through the mixtureto remove impurities. While deodorization steps can be used to removesome of the organohalo, glycidyl or other oxirane species from short andmedium chain triglycerides, deodorization alone, without the addition ofcarboxylate anion and cation counterion, is not sufficient tosubstantially reduce the amount of these impurities present in thetriglyceride oils. Moreover, deodorization of heavier triglycerides suchas C₁₂ chains and higher, can actually cause the formation oforganohalo, glycidyl or other oxirane species in these heaviertriglyceride oils.

The present technology may be used for the reduction or removal oforganohalo, glycidyl, or oxirane species from any triglyceride oilsknown in the art, including, but not limited to, edible and food gradeoils and their analogs (monoglycerides and diglycerides), lubricatingoils, synthetic oils, specialty polymers and personal care applications,and pharmaceuticals.

The presently described technology and its advantages will be betterunderstood by reference to the following examples. These examples areprovided to describe specific embodiments of the present technology. Byproviding these specific examples, it is not intended limit the scopeand spirit of the present technology. It will be understood by thoseskilled in the art that the full scope of the presently describedtechnology encompasses the subject matter defined by the claimsappending this specification, and any alterations, modifications, orequivalents of those claims.

EXAMPLES Example 1 Removal of 3-chloro-1,2-propanediol diesters fromCapric/Caprylate Acids

Extra MCPD was added to a triglyceride reaction stream to determine ifthe base could remove the MCPD from the triglyceride oil. Glycerol(23.62 g, 0.256 mol), capric/caprylic fatty acids (129.1 g, 0.822 mol),preformed capric/caprylic fatty acid esters of 3-chloro-1,2-propanedioland C8/C10 fatty acids (3.05 g, 0.0078 mol) and potassium carbonate(base, 2.03 g, 0.0147 mol) were combined. The reaction was mixed andheated to about 210° C. over 11.5 hours. After holding at about 150° C.for 1 hour, the reaction solution was heated to about 210° C. over onehour and then held at about 210° C. for 3 hours. The solution wasfiltered using 50 micron filter paper. After the second hold period, noorganochloro species were detected by GC.

Example 1 illustrates that a base can be added during the manufacture ofa triglyceride oil to effectively remove MCPD impurities from theresulting triglyceride oil.

Example 2 Removal of 3-chloro-1,2-propandiol in a Glyceride ReactionSystem

This example illustrates that the addition of a base to a triglyceridereaction stream is effective to remove MCPD impurities duringmanufacture of the triglyceride oil. Caprylate/capric fatty acids (52%caprylate, 640.45, 4.08 mol), glycerol, (108.7 g, 1.18 mol) andpotassium carbonate (base) were combined. The mix was held for 20minutes. After the offgassing has stopped, carbon (3.54 g) and3-chloro-1,2-propanediol (2.79 g, 0.0244 mol) were added to the reactionmixture. The mix was heated to about 235° C. over 2 hours and held atabout 235° C. for four additional hours. Upon cooling, the mix wasfiltered and unreacted fatty acids were converted to methyl esters (vialmethanol and sulfuric acid). Upon analysis of the triglyceride oil by anoutside laboratory, Eurofins Central Analytical Laboratories, Metairie,La., the total 3-MCPD (free and bound) was found by GC mass spectrometryto be less than 0.15 mg/kg of total composition.

Example 3 Removal of 3-MCPDs During Triglyceride Formation

This example illustrates that the addition of a base to a reactionstream containing an alkyl ester feedstock is effective to remove orprevent the formation of MCPD impurities during the manufacture of thetriglyceride oil. Methyl esters of C8/C10 fatty acids (500 g) andpotassium carbonate (1.7 g) were combined and heated to about 175° C.Glycerol (78.6 g) was then added to the reaction mixture and the mixturewas heated to about 235° C. and held at about 235° C. for 3 hours.Excess methyl esters were removed in vacuo and the resultanttriglyceride was filtered under vacuum using 50 micron paper. Analysisby the outside lab, Eurofins Central Analytical Laboratories, Metairie,La., showed the level of total 3-MCPD (free and bound) to be less thanabout 0.15 mg/kg using GC mass spectrometry.

Example 4 Removal of Glycidyl Esters from a Pre-Formed Triglyceride

This example illustrates that a base (and additional fatty acids) can beadded to a triglyceride oil product to effectively remove glycidyl esterimpurities. A deodorized caprylate/capric triglyceride (99.95 g), C8/C10fatty acids (3.3 g) and potassium carbonate (0.45 g) were combined andheated to about 200° C. At about 200° C., glycidyl butyrate (1.54 g) wasadded. The mixture was incubated at about 200° C. for 1 hour, and thesample was filtered and analyzed for glycidyl content. No glycidylspecies were detectable by gas chromatography.

Example 5 Removal of Organochloro and Oxirane Species in a GlycerideReaction System at Reaction Temperature

This example illustrates that the addition of a base to a triglyceridereaction stream is effective at triglyceride reaction temperatures toremove or prevent the formation of MCPD impurities during themanufacture of the triglyceride oil. C8/C10 fatty acids (647.69 g, 4.125mol), sodium carbonate (2.00 g, 0.0189 mol) and carbon (3.48 g) werecombined and heated to about 210° C. Glycerol (108.85 g, 1.182 mol) wasadded over four hours. The mix was heated to about 245° C. and held for6 hours. The soap concentration was about 8,960 ppm. The carbon wasremoved via filtration. Upon analysis by an outside laboratory, thetotal 3-MCPD (free and bound) was found to be less than 0.15 mg/kg asdetermined by GC mass spectrometry.

Example 6 Removal of Chloro and Oxirane Species in a Glyceride ReactionSystem at Reaction Temperature

In this example, a run similar to Example 5 was conducted using similarreactants and similar reaction conditions, except that potassiumcarbonate was used as the base and the soap concentration was about1,180 ppm. Upon analysis by an outside laboratory, the total 3-MCPD(free and bound) was found to be less than 0.15 mg/kg as determined byGC mass spectrometry.

This example illustrates that, in comparison to Example 5, a lower soapconcentration can be used which is still effective to remove or preventthe formation of MCPD impurities.

Example 7 Removal of Chloro and Oxirane Species in a Glyceride ReactionSystem at Reaction Temperature

In this example, a run similar to Example 5 was conducted using similarreactants and similar reaction conditions, except that the soapconcentration was about 660 ppm. Upon analysis by an outside laboratory,the total 3-MCPD (free and bound) was found to be 0.23 mg/kg as measuredby GC mass spectrometry. Untreated medium chain triglycerides (MCTs)from this manufacturing process typically have MCPD levels of greaterthan 0.5 ppm as measured by GC mass spectrometry.

This example illustrates that, although the soap concentration of 660ppm was not effective under the particular time and temperatureconditions employed in this example to reduce the MCPD levels tonon-detectable levels, it was still effective to reduce the MCPDimpurities by about 50% compared to typical levels found in a similaruntreated triglyceride. It is expected that at the soap concentration of660 ppm, increasing the reaction temperature or reaction time or bothwould have resulted in a total MCPD concentration of less than 0.15mg/kg.

Example 8 Treatment of a crude oil stream at 200° C.

An unrefined triglyceride of C₈-C₁₀ fatty acids (612.56 g) was obtainedfrom a typical Production run (48,000 lb crude product). To thismaterial potassium carbonate (0.76 g, 0.12 wt %) was added. Theresulting soap concentration was about 3,500 ppm. The reaction mix washeated to about 200° C. over 2 hours and then held at about 200° C. foran additional 2 hours. Upon cooling the mix was filtered. The MCPDlevels in the unrefined triglyceride before and after treatment with thebase were measured by GC mass spectrometry by an outside laboratory, SGSGmbh Hamburg, Germany. After treatment, the MCPD level in the filteredstream was reduced to below detectable limits (<0.10 mg/kg) compared toa starting MCPD concentration of 0.57 mg/kg.

Example 9 Treatment of a Crude Oil Stream at 170° C.

An unrefined triglyceride of C8-C10 fatty acids (604.97 g) was obtainedfrom a typical Production run (48,000 lb crude product). To thismaterial potassium carbonate (0.85 g, 0.14 wt %) was added. Theresulting soap concentration was about 3,970 ppm. The reaction mix washeated to about 170° C. over 2 hours and then was held at about 170° C.for an additional 2 hours. Upon cooling the mix was filtered. The MCPDlevels in the unrefined triglyceride before and after treatment with thebase were measured by GC mass spectrometry by an outside laboratory, SGSGmbh Hamburg, Germany. After treatment, the MCPD level in the filteredstream was reduced to 0.33 mg/kg as compared to a starting MCPDconcentration of about 0.57 mg/kg.

Examples 8 and 9 illustrate the relationship between reaction time,reaction temperature, and soap concentration in removing theorganochloro and oxirane species. The reaction temperature of Example 9was lower than Example 8 (170° C. compared to 200° C.) and the soapconcentration was slightly higher (3,970 ppm compared to 3,500 ppm),while the reaction times were the same. The conditions of time,temperature and soap concentration employed in Example 8 were sufficientto remove the MCPD impurities to below the detectable limits, whereasthe conditions employed in Example 9 were sufficient to remove some ofthe MCPD impurities (about a 40% reduction). It is expected that theMCPD concentration would have been below detectable limits (less than0.10 mg/kg) in Example 9 if a higher concentration of soap had beenused, keeping the reaction temperature and reaction time of Example 9the same. Alternatively, a higher reaction temperature or longerreaction time, or both, could have been used in Example 9 to remove moreof the MCPD impurities at the given soap concentration.

The presently described technology is now described in such full, clear,concise and exact terms as to enable any person skilled in the art towhich it pertains, to practice the same. It is to be understood that theforegoing describes preferred embodiments of the technology and thatmodifications may be made therein without departing from the spirit orscope of the invention as set forth in the appended claims.

In the present specification, use of the singular includes the pluralexcept where specifically indicated.

The invention claimed is:
 1. A process of preparing a carboxylic acidester stream with reduced levels of organohalo, glycidyl or otheroxirane species, the process comprising: adding to the carboxylic acidester stream an effective amount of a carboxylate anion to react withall of the organohalo, glycidyl and oxirane species present in thecarboxylate acid ester stream at a temperature of 80° C. to 275° C. 140°C. to 250° C., wherein the carboxylate anion reacts with the organohalo,glycidyl or oxirane species for a sufficient amount of time to provide acarboxylic acid ester stream with reduced levels of organohalo, glycidylor other oxirane species.
 2. A process of removing organohalo, glycidylor other oxirane species from a triglyceride oil comprising the stepsof: mixing an effective amount of at least one base to an effectiveamount of at least one fatty acid to produce an effective amount of atleast one carboxylate anion and corresponding cation counterion that issufficient to remove the organohalo, glycidyl or other oxirane speciesfrom the triglyceride oil; mixing the effective amount of thecarboxylate anion with the triglyceride oil at a temperature of about80° C. to about 275° C. 140° C. to about 250° C., wherein thecarboxylate anion reacts with the organohalo, glycidyl or oxiranespecies for a sufficient amount of time to provide a triglyceride oilproduct with reduced levels of organohalo, glycidyl or other oxiranespecies.
 3. A process of removing or preventing the formation oforganohalo, glycidyl or other oxirane species during a processing or amanufacturing procedure for a triglyceride oil comprising the steps of:making a triglyceride oil feedstock; adding a sufficient amount of atleast one base to react with a sufficient amount of fatty acid withinthe triglyceride oil feedstock to produce a carboxylate anion and acation counter ion in an amount sufficient to react with the organohalo,glycidyl and oxirane species present in the feedstock; incubating thefeedstock containing the at least one base at a temperature of about 80°C. to about 275° C. 140° C. to about 250° C. for a sufficient amount oftime to produce a triglyceride oil with reduced levels of organohalo,glycidyl or other oxirane species.
 4. The process of claim 1, whereinthe carboxylate anion is added at the start of the oil processing ormanufacturing procedure.
 5. The process of claim 3, wherein the processfurther comprises adding a sufficient amount of at least one fatty acidto react with the at least one base to produce the carboxylate anion andcation counter ion.
 6. The process of claim 1, wherein the carboxylateanion is added after one or more of the processing steps, wherein theprocessing steps comprise refining, degumming, deodorization, washing,bleaching, distillation, or any combination thereof.
 7. The process ofclaim 3, wherein the carboxylate anion is added after the steps ofprocessing to a purified triglyceride oil.
 8. The process of claim 3,wherein the triglyceride oil is a C2 to C24 chain triglyceride.
 9. Theprocess of claim 8, wherein the triglyceride oil is a C2 to a C18 chaintriglyceride.
 10. The process of claim 8, wherein the triglyceride oilis an edible oil.
 11. The process of claim 10, wherein any residualorganohalo, glycidyl or other oxirane species in the edible oil isremoved by a further step of: deodorizing the triglyceride oil.
 12. Theprocess of claim 3, wherein the cation counterion of the carboxylateanion is an alkali metal, an alkaline earth metal, a transition metal, anitrogen- or phosphorous-containing cationic species, or combinationsthereof.
 13. The process of claim 3, wherein the carboxylate anion andcation counter ion is of the formula:

wherein R is a C2 through C24 carbon and M is an alkali metal, analkaline earth metal, a transition metal, or a nitrogen- orphosphorous-containing cationic species.
 14. The process of claim 3,wherein the at least one base is added in excess of the amount of theorganohalo, glycidol or oxirane (ethylene oxide) species within thetriglyceride oil.
 15. The process of claim 14, wherein the base isprovided in about 1.1 to about 10,000 fold molar excess of the amount oforganohalo, glycidyl or other oxirane species in the triglyceride oil.16. The process of claim 14, wherein the base is provided in an amountsufficient to produce at least 350 ppm or more of the carboxylate anion.17. The process of claim 3, wherein the processed triglyceride oilcomprises less than about 0.5 ppm of organohalo, glycidyl or otheroxirane species.
 18. The process of claim 17, wherein the triglycerideoil comprises less than about 0.15 ppm of organohalo, glycidyl or otheroxirane species.
 19. The process of claim 18, wherein the preferredtemperature range is about 120° C. to about 250° C.
 20. The process ofclaim 19 17, wherein the preferred temperature range is from about 180°C. to about 230° C.
 21. The process of claim 3, wherein the carboxylateanion is added in excess of the amount of the organohalo, glycidol oroxirane (ethylene oxide) species within the triglyceride oil.
 22. Theprocess of claim 21, wherein the carboxylate anion is provided in anamount of at least 350 ppm or greater.
 23. The process of claim 1,wherein the processed carboxylic acid ester stream comprises less thanabout 0.5 ppm of organohalo, glycidyl or other oxirane species.
 24. Theprocess of claim 23, wherein the carboxylic acid ester stream comprisesless than about 0.15 ppm of organohalo, glycidyl or other oxiranespecies.
 25. The process of claim 1, wherein a metal halide salt ormetal alkoxide species resulting from the reaction are removed by anadditional processing step.
 26. The process of claim of 25, wherein theadditional processing step is selected from the group consisting offiltration, washing, centrifuging, winterization, extraction,acidification with a mineral acid, settling, and miscella refining. 27.The process of claim 1, wherein a sufficient amount of time is greaterthan 30 minutes.
 28. The process of claim 27, wherein a sufficientamount of time is one hour or greater.
 29. The process of claim 2,wherein the triglyceride oil product is essentially free of organohalo,glycidyl or oxirane species.
 30. The triglyceride oil product withreduced levels of organohalo, glycidyl or oxirane species produced bythe process of claim 2, wherein reduced levels of organohalo, glycidylor oxirane species are in comparison to an oil product that does notundergo reaction with an carboxylate anion.
 31. The triglyceride oilproduct of claim 30, wherein the oil product is essentially free oforganohalo, glycidyl or oxirane species.
 32. The triglyceride oilproduct of claim 30, wherein the triglyceride oil product comprises lessthan about 0.5 ppm of organohalo, glycidyl or other oxirane species. 33.The triglyceride oil product of claim 30, wherein the triglyceride oilproduct comprises less than about 0.15 ppm of organohalo, glycidyl orother oxirane species.
 34. The triglyceride oil product of claim 33,wherein the oil product is an edible oil, a synthetic oil, a vegetableoil or an animal fat oil.
 35. The process of claim 1, wherein thecarboxylic acid ester stream comprises a carboxylic acid, an alkyl esterof a carboxylic acid, carboxylic anhydride, carboxylic derivatives, acylhalides, carbonates, anhydrides, heteroatom derivatives or combinationsthereof.
 36. The process of claim 3, wherein the triglyceride oilfeedstock comprises a carboxylic acid, an alkyl ester of a carboxylicacid, carboxylic anhydride, carboxylic derivatives, acyl halides,carbonates, anhydrides, heteroatom derivatives or combinations thereof.37. The process of claim 2, wherein the triglyceride oil is selectedfrom the group consisting of coconut oil, cochin oil, corn oil,cottonseed oil, linseed oil, olive oil, palm oil, palm kernel oil,peanut oil, soybean oil, sunflower oil, tall oils, tallow, lesquerellaoil, tung oil, tea seed oil, whale oil, sesame seed oil, safflower oil,rapeseed oil, fish oils, avocado oil, mustard oil, rice bran oil, almondoil, walnut oil, derivatives thereof and combinations thereof.